Mechanism to prevent brake chatter



' Aug. 30, 1932. RO HRO K 1,874,354

MECHANISM TO PREVENT BRAKE CHATTER Filed June 28, 1930 1% WMW akbozwuf Patented Aug. 30, 1932 UNITED, STATES *PATE-ANTTOFFICE GEORGE L. ROTHROCK, or nETnoiT, MIcHIeAn, assreuonTo GENERAL MOTORS con-i? POR-ATION, or DETROIT, mromean, AJconroRATIon or DELAWARE 1 MECHANISM To rnnvnnr isnnxn CHATTER Application filed June as,

This invention relates to brakes and particularly to brakes for use with vehicle wheels.

The object of the invention is to prevent l brake drum substantially on line 1-1 of Fig. 2.

Fig. 2 is a vertical section through the drum on line 2-2 of Fig. 1.

Fig. 3 is a view'of a vehicle wheel partly in elevation and partly in section.

Referring by numerals to the drawing, there is shown at 5 a live axle used for driving the wheel. The wheel illustrated is a spoked wheel and is represented by numeral 9. The wheel is provided with a wheel hub '11.

The wheel carries also a brake drum 13. To a flange on the axle housing 16 is secured a dust shield 17 and also a plate o 19 which serves as a brake shoe anchorage.

and a ball bearing 27 is located between the extension and the wheel hub 11. The wheel hub 11 and the extension 25 have shoulders to engage the outer and inner races of the hearing as clearly shown in Fig. 1. An anextended within the wheel hub 11 and en'- gages the outer side of the outer bearing race. In the construction shown in the drawing the bearing 27 for the rotatable support of the wheel is located somewhat inwardly from the vertical plane of the wheel center and befor the purpose of locating the bearing between the forces due to brake application, and. 0 the reactionary force due to the weight of the car, and operable through the vertical "1930. serial 116.,464555.

There is also shown an oil guard 21 secured nular locking ring 26 is threaded on the end of extension 25 to engage the outer side ofthe inner bearing race. A driving hub29' used for transmitting the drive from the live. axle to the wheel in a well known manner is.

tween that plane and the .mid plane of the brake shoes. Thislocation has been adopted plane of the wheel. This is done to reduce the maximum load on the bearingi l In Fig. 3 an arrow W is used to represent .the reaction .dueto the weight of the car and operating through the plane of the wheelf Theletter F representst he force applied againstthe brake drum as the result ofbra-ke application. This force F is illustrated in Fig.2 as extending upwardly and forwardly, and; represents the action i'n-the case of the self-actuating shoe effective for resisting forward movement of the vehicle. There will bea similar upward and rearwardlydirected force for the other shoe which issmalle'r and for present purposes :may be" disregarded The-force F has" a vertical component-F which fallsat a distance L (see Fig. 3) from the bearingand inwardly from the bearing. The-reaction-W passes at a distance L from the bearing and outwardly from the plane ofthe bearing. "Each of these two'forces tends to rotate thewheel about its bearing, the direction of rotation at any one time depending upon the vrelative magnitude of the forces F andW." 1

When the brake is not applied obviously the forceW is not resisted by any force F.

' As the, brake is 'beingapplied a condition occurs] during light braking application in which the two forces W and-F approximatel vbalance'eachiother. .When now the force slightly exceeds the force W the wheel is rotated about the; bearing, so that the drum ;tion As1aresult the engagement of the shoe and drum which is in a generally vertical direction; is somewhat modified and there is "a-horizontal component in the reaction between-the drum and the shoe. Thishori-v zontal component is intended to overcome the brake chattering explained above. The hori- ,zontal force is received and resisted by one or more brake shoe guides. These guides are designated on the drawing by numeral 31 in the case of the long self-actuating shoe, and by 33 in the case of the shorter shoe. They may be fixed in position by fastening means 35 which is used to attach them to the dust shield and to the plate 19. At their ends these guides 31 and 33 engage the edges of the shoes as shown in the drawing? By the arrangement described, the posi- "tion of the bearing for supporting the wheel on the axle housing has been advantageously located between the planes of the forces F and W. By designing the drum as ex plained above and by using the horizontal thrust-resisting plates chatter has been avoided. f I claim: a

' 1. In combinatioman axle, a wheel, a hearing between the axle and wheel located out of the plane of the wheel, said bearing constituting the only bearing support for said wheel, a brake including a drum carried by said wheel, and shoes engaging the drum on that side of the bearing opposed to the wheel plane, said brake constructed to produce a horizontal component in the reaction between I the drum and the shoe.

2. 'In combination, an axle, a wheel, a hearing between the axle and wheel located out of the plane of said wheel, said bearing constituting the only bearing-support for said wheel, a brake including a drum carried by the wheel and shoes engaging the drum on the side of the bearing opposed to the wheel plane, said drum having a tapered flange 'whereby the engagement of the shoe and drum is accompanied by a horizontal eom- 'ponent to prevent brake chatter.

' gether with means to resist said horizontal 3. The invention defined by claim 2, to-

component.

4. The invention defined by claim 2, to-' gether with means rigid with saidaxle and engaging said brake shoe to resist said hori-- zontal component.

5. In combination, a vehicle axle, a wheel, a bearing for said wheel, said bearing affording the only rotary support for said wheel, the vertical plane of said wheel being dis posed on one side of said bearing and means associated with said wheel and axle to check I wheel rotation, said means positioned on the other side of said bearing, and constructed to provide a horizontal component when the brake is applied to-resist chatter when the intensity of the braking means approximates the reaction of the load supported by the wheel.

'6. The invention defined by claim 5, to-

, gether with means engaging a part of said braking mechanism to resist said horizontal component. I

In'te'stimony whereof I aflix my signature. GEORGE L. ROTHROCK. 

